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Biomedical subjects

E Morgan

Publications and source records attributed to E Morgan.

At least 109 records · Page 6Linked to original sources
PubMed1981

Relationship of a leukemia-associated antigen to the presence of lymphoblasts in the peripheral blood in children with acute lymphocytic leukemia.

Peripheral blood samples from 57 children with newly diagnosed E-rosette-negative, surface-immunoglobulin negative acute lymphocytic leukemia (ALL) were studied for the presence of a leukemia-associated antigen (ALLA). Ficoll-Hypaque separated cells were tested using a rabbit antiserum to human null lymphoblasts and an indirect immunofluorescent assay. The percentage of ALLA-positive cells were compared to the percentage of lymphoblasts determined by differential counts of a Wright-Giemsa-stained smear of a concurrently obtained peripheral blood sample. The mean ratio of percentage of lymphoblasts to percentage of ALLA-positive cells was 0.90. However, in 13 patients, the ratio of percent of ALLA-positive cells to percent of lymphoblasts was equal to or greater than 2:1. In the blood of 6 additional children (5 newly diagnosed, 1 relapsed patient) in whom no morphologically identifiable lymphoblasts were detected. ALLA-positive cells were present (7%-49%). These results indicate that testing for ALLA-positive cells in a sensitive technique for detection of leukemic cells in children with ALLA-positive ALL.

Ammonium Chloride↗
PubMed1981

Relation of particle dimension to carcinogenicity in amphibole asbestoses and other fibrous minerals.

In 72 experiments, durable minerals in the form of particles on respirable size and of wide chemical and structural varieties, were implanted in the pleurae of outbred female Osborne- Mendel rats for periods of more than 1 year. The incidence of induced malignant mesenchymal neoplasms correlated well with the dimensional distribution of the particles. The probability of pleural sarcoma correlated best with a number of fibers that measured 0.25 micro or less in diameter and more than 8 micrometer in length, but relatively high correlations were also noted with fibers in other size categories having diameters up to 1.5 micrometer and lengths greater than 4 micrometer. Morphologic observations indicated that short fibers and large-diameter fibers were inactivated by phagocytosis and that negligible phagocytosis of long, thin fibers occurred. The wide variety of compounds used in these experiments suggested that the carcinogenicity of fibers depended on dimension and durability rather than on physicochemical properties.

Animals↗
PubMed1981

Acute lymphocytic leukemia in a child with congenital xanthine oxidase deficiency: implications for therapy.

Xanthine oxidase deficiency was identified in a 16-year-old girl with acute lymphocytic leukemia (ALL). Despite the enzyme deficiency, the patient tolerated high doses of 6-mercaptopurine (6-MP), a drug which is normally inactivated by the action of xanthine oxidase. This rate clinical situation may be analogous in the practice to that of the patient receiving 6-MP who is also given allopurinol, which inhibits xanthine oxidase activity. The implications of these observations on the determination of appropriate drug dosages for patients receiving these two agents are discussed.

Adolescent↗
PubMed1980

The preservation of nerve cells in rat neostriatal slices maintained in vitro: a morphological study.

The in vitro preservation of neurons in 300 micron thin neostriatal slices, which are routinely used for electrophysiological studies, was examined by light and electron microscopy and was compared to 700 micron thick neostriatal slices. The thin slices displayed well-preserved cells after up to 5 h of incubation. This finding correlated well with whether electrical activity could be recorded. In cross-section, the thin slices consisted of three layers: the inner layer contained many intact cells (80%) and was sandwiched between the outer layers where deteriorating cells predominated. In contrast to the thin slices, the thick slices (700 micron) displayed no layering of intact cells in cross-section. Instead, the majority of cells throughout these thick slices was swollen (98%), with only small patches of intact cells. Two types of deteriorating cells were apparent: swollen cells and dark (pycnotic) cells. The proportion of swollen cells increased with incubation time. In the thin slices this swelling occurred in the outer layers with the middle layer of intact cells remaining relatively unchanged over long incubation periods, whereas all cells in the thick slices were swollen after 2 h of incubation. Dark cells were localized to the outer portion of both slices and the number of such dark cells did not change with incubation time.

Animals↗
PubMed1978

Undifferentiated sarcoma of the kidney: a tumor of childhood with histopathologic and clinical characteristics distinct from Wilms' tumor.

The pathological and clinical features of 123 patients with Wilms' tumor diagnosed between 1961 and 1977 were analyzed. A subgroup of nine patients with distinctive histology characterized by the presence of exclusively sarcomatous elements was identified. These patients were indistinguishable clinically from the other patients with Wilms' tumor and were treated as Wilms' tumor. The rate of recurrence in this group of sarcomatous Wilms' tumor was very high (7/9) and long-term disease-free survival correspondingly low )3/9 free of disease from 15 months to nine years) when compared to the patients with classical Wilms' tumor (50% recurrence rate and 71% currently free of disease). In addition, patients with metastases (seven of seven patients with recurrence had skeletal involvement as contrasted to one of 50 patients with metastatic classical Wilms' tumor). We conclude that the "sarcomatous Wilms' tumor" represents a distinct clinicopathological entity identifiable morphologically at diagnosis, best described as renal sarcoma and that in the future optimal treatment of this disease may vary somewhat from the treatment of classical Wilms' tumor.

Bone Neoplasms↗
PubMed1978

Hodgkin disease and red cell aplasia.

A teenage boy with mixed-cellularity Hodgkin disease presented with severe anemia secondary to pure red cell aplasia of marrow without evidence of lymphomatous infiltration or hemolysis. In vitro studies of the patient's serum demonstrated an inhibitor of erythropoietin activity which appeared to be an IgG but which did not directly bind erythropoietin. The patient's anemia resolved and the inhibitor disappeared following chemotherapy for Hodgkin disease. Presumably, the inhibitor was directed at a very early stage of red blood cell production. This phenomenon may be related to other autoimmune manifestations occasionally seen in patients with lymphomas. The case is presented to bring attention to the unusual occurrence of red cell aplasia in Hodgkin disease. Several hypotheses concerning significance and etiology of the anemia are detailed.

Adolescent↗
PubMed1977

The value of maintenance therapy following treatment of central nervous system leukemia.

The efficacy of intrathecal (IT) maintenance chemotherapy following central nervous system (CNS) leukemia was demonstrated in a retrospective study of 77 such episodes. The median durations of CNS and bone marrow (BM) remissions were significantly longer for the 41 maintained episodes (10+ and 9.5 months, respectively) compared with the 36 unmaintained episodes (4 and 2 months, respectively). Patients were comparable in each of these two groups. For those patients receiving maintenance therapy, there appeared to be an advantage in using four or more doses of IT medications for treatment of CNS leukemia, regardless of the number of doses necessary to clear the cerebrospinal fluid (CSF).

Antineoplastic Agents↗
PubMed1977

Isolation of the cytoplasmic granules of guinea pig basophilic leukocytes: identification of esterase and protease activities.

Procedures were developed for isolating highly purified cytoplasmic granules of basophilic leukocytes from guinea pig peripheral blood. The methods involved disruption of cells in 0.34 M sucrose followed by a series of membrane filtrations and fractionation on sucrose density gradients. These preparations, up to 95% pure basophil granules by electron microscopy, contained a mixture of neutral esterases-proteases including caseinolytic activity; both trypsin- and chymotrypsin-like serine hydrolases were identified by means of appropriate inhibitors. Localization of at least one such activity to the basophil granule was confirmed by a cytochemical method; this activity was absent in contaminating lymphocytes and eosinophils. By contrast, several lysosomal enzymes, lactic dehydrogenase, and plasminogen activator activity, present in cell homogenates, were absent from purified granules. The granule matrix of guinea pig basophils, unlike the cytoplasmic granules of other granulocytes or mast cells, was little altered by high or low salt concentration but was disrupted into insoluble fragments by 0.01 N HCl and by Triton X-100. Granules were solubilized by papain and by urea-SDS but enzyme activity was destroyed. Triton X-100 incubation with freeze-thawing proved to be the optimal method for extracting esterase activities. Esterase activities were not released from basophils under conditions of anaphylactic degranulation that liberated the great majority of basophil granule histamine.

Animals↗